Telephone-switchboard.



No. 855,391 PATENTED MAY 28, 1907. J. M. DOSBAUGH.

TELEPHONE SWITGHBOARD.

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No. 8, 55,391. PATENTED MAY 28, 1907.

-. J. M. DOSBAUGH.

TELEPHONE SWITGHBOARD.

APPLICATION FILED AUG-1. 1905.

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JOHN M. DOSBAUGH, OF CEDAR VALE, KANSAS.

TELEPHONE-SWITCHBOARD.

Specification of Letters Patent.

Patented May 28, 1907.

Application filed August 1,1905. Serial No. 272,144.

T at whom it may concern.-

Be it known that 1, JOHN M. DOSBAUGH, a States, and. a resident of Cedar Vale, in the county of Chautauqua and State of Kansas, have invented a new and Improved Telephone-Switchboard, of which the following is a full, clear, and exact description.

My invention relates to telephony, my more particular object being to produce an improved type of switch-board suitable for use at central stations.

Reference is to be had to the accompanying drawings forming apart of this specificacation, in which similar characters of refer ence indicate corresponding parts in all the figures.

Figure 1 is a side elevation, partly diagrammatic, showing a part of my improved switch-board in normal condition; Fig. 2 is a somewhat similar View showing the condition of the switch-board. when connection is made for one subscriber; Fig. 3 is a side elevation, partly in section, showing the selective frame; Fig. 4 is a diagram of certain electric connections, a part of the selective frame being shown perspectively; and Fig. 5 is a detail perspective view of one of the pawls used for holding the push rods.

Upon a base 6 are mounted two standards 7, and within these standards is a swinging frame 8 supported upon journals 9. Several pairs of contact strips 10, 11, 10, 11 are mounted rigidly within the swinging frame. Connected with these contact strips are Wires 12, 13, 12 13. Below each pair of contact strips 10, 11, 10, 11 is a contact spring 14, 14 insulated therefrom by means of a bar 15 of insulating material. Each bar 15, 15 is supported by a spring 14, 14 The arrangement is such that when one of the bars 15, 15 is depressed, the spring 14, 14 below it is flattened, and thus brought into engagement with its proper, spring 16, 16*. Each spring 14, 14 etc. is connected with a separate wire 17, 17 17 etc., and each spring 16, 16 etc., is connected with a wire 18, 18 18 The wires 17, 17 and 17 are in parallel with each other with respect to a A number of lamps 20, 20, 20 are used as busy signals and are in parallel with each other by means of a wire 21 and the battery 19. Wires 22, 23 lead to the operators telephone. To the wire 22 are connected the wires 13, 13 etc., while the wire 23 is connected by wires 14, 25 and 26 with contact members 28, 28, 29, the wire 12 be ing connected with a contact member 27, the wire 12 with a contact member 27 the wire 12 with a contact member 29, and so on through the series as indicated in Fig. 1. A lever 30 is provided with a handle 32 and. is journaled upon'a pivot 31 so as to swing. The lower end of this lever is provided with a contact plate 33 insulated. from the lever by means of a block 34 of insulating material. This contact plate is adapted to close communication between successive pairs of contact members 27, 28; 27 28; 29, 29. A pitman 35 is j ournaled at 36 upon the lever 30 and is connected with the swinging frame 8 at the point 37 as shown in Figs. 1 and. 3.

A number of strips 39, are disposed in pairs and arranged upon opposite sides of insulating rods 38 which depend from the respective levers 43. The lower ends of the conducting strips 39, 40 terminate in contact members 41, 42, adapted to engage the contact strips 11, 10, 11 10 when lowered for the purpose as hereinafter described. A separate lever 43 is connected with each rod 38 and is journaled upon a pivot 44. Each rod 38 is connected to springs 45, 46, these springs normally maintaining the rod in a vertical position and, also serving as conductors. Adjacent to the springs 45 are other springs 45, forming a row entirely across the machine as indicated in Fig. 3. The several springs 46 are arranged in like manner as the springs 45, 45. The springs are connected at 47 with a plate 48 of insulating material as indicated in Fig. 3. Mounted upon this plate are two strips 49, 59 of insulating material, the strip 50 being provided with contact members 51., 52 and 53, and the strip 49 being similarly provided with contact members 54, 55 and 56, these contacts being duplicated clear across the frame. The contact members 52, 55 are connected together by a button 57 of insulating material, whereby both of these springs 52, 55 may be moved at the same time.

Each contact spring-52 is connected with a separate subscribers line 58. A separate wire 57, 63 connects each contact spring 51 with one of the conducting strips 39 through. a spring 46. Each contact spring 53 is con nected by a wire 59 with a wire 61, the latter being in communication with a generator 62. From each contact spring 55 a wire 65 leads to the station of the subscriber, say subscribcr No. 1, and from this subscribers station a wire 64 leads back to one of the contact springs 52. A wire 66 leads from another subscribers station to a contact member 55, and a wire 58 in communication with the same station leads to a contact member 52. From .the generator 62 a wire 67 leads to the contact member 56, and from this wire 67 a wire 68 branches off to another one of the contact members 56. Each contact member 54 is connected by a wire 69, 70 with. a contact strip 40 through a spring 45.

A bracket 71 is provided with an arm 72 supporting a bell crank lever 73, the latter being secure by a connection 74 and a spring 75 to the lever 43, so that when the bell crank 73 is rocked the lever 43 is moved from its normal position indicated in Fig. 1 to the osition indicated by the center of Fig. 2. A push rod 76 is slidably mounted within the bracket 71. Below this push rod is a magnet 77, which attracts an armature 78, the latter being mounted upon a spring pawl 79 and normally raised by a leaf spring 80. spiral spring 81, presses against a pin 82 extending through the push rod 76, and nor mally pushes this rod to the right according to the views shown. The push rod 76 is pro vided with teeth 83, 84, S5 to be engaged by the pawl 79, thus holding the push rod in different positions. The spring pawl 79 is provided with an aperture 79 through which the push rod 76 passes, and is also provided with a point 79 as indicated in Fig. 5. A number of relays 86 are each provided with contacts 87 and 87 and connected by wires 38, 89 with respective pairs of the springs 45, 46. From the contacts 87 wires 91 lead to the battery (indicated by legend), and from here the wires 93 lead to the magnets 77. From these magnets wires return to the contacts 87. The operator,by grasping the handle 32 and swinging the lever 30 upon the journal 31, causes the rod 35 to rock the frame 8 into such position that the contact members 41, 42 may be brought into alinement with any pair of the contact strips 1.1, 10, 11 10. The lever 43 then being rocked or brought into the position indicated in Fig. 2, contact is made between the contact members 41, 42 and the contact strips, as will be understood. from Fig. 2.

The operation of my device is as follows The normal position of the device is indicated in Fig. 1, the tooth 84 now resting against the pawl 79. Suppose, now, that subscriber No. 1 wishes the central station to connect his station with that of subscriber No. 2. Subscriber N0. 1 energizes the wires 64, 65 in the usual manner, and the alarm at the central station is made by the following "circuit: Line wire 64 of subscriber No. 1, contact members 52, 51, wire 63, shunt wire 89, relay 86, wire 88, wire 70, contact members 54, 55, and line wire65 back to the station of subscriber No. 1. This energizes the relay 86 and closes the contacts 37 and 87 thereby completing a local circuit as follows: Battery 92, wire 91, contacts 87 87, wire 90, magnet 77, wire 93 and battery. This energizes the magnet 77 and causes the pawl 79 to be lowered slightly, so that the tooth S4-can pass through the aperture 79. (See Fig. 5). This allows the rod 76 under tension of the spring 81 to assume the position indicated by dotted lines in the center of Fig. 1. The operator thereupon. knows that subscriber No. 1 desires to secure his attention. The operator then pushes in the re d 76, appertaining to station No. 1, so that this rod assumes the position indicated by full lines in the center of Fig. 2, the tooth 85 now being held by the pawl 79 and the spring 81 being cemressed as shown. This movement rocks the bell crank 73 and lovers the lever 43. Before pushing in the rod 76 as just described, however, the operator first grasps the handle 32 and moves the lever 30 into proper position to place the contact members 41, 42 in alinement with. one pair of the contact strips 10, 1.1 or 10 11. This havingbeen done, the movement of the lever 43 causes the contact members 41, 42 to move into engagement with thecontact strips as indicated in the lower part of Fig. 4. The operators telephone is now in the following circuit: Line wire 64, contact members 52, 51, wire 63, spring 46, conducting strip 39, contact member 41, contact strip 11 (see Fig. 4) wire 1.3, wire 22 tooperators telephone, thence from wires 23 and 24 to contact point 28, contact plate 33, contact point 27, wire 12, contact strip 10, contact member 42, conducting strip 40, spring 45, wire 70, contact members 54, 55, and wire 65. The subscriber No. 1 now informs the operator ol" the identity of the subscriber with which he wishes to converse, say, for instance, subscriber No. 2, and the operator thereupon pushes in the push rod 7 6 appertaining to the station of subscriber No. 2, the distance to which the rod is pushed. being considerable as indicated by dotted lines in Fig. 2. The result is that the rod 76 presses the button 57 inward, so that the contact members 52, engage the contact members 53, 56. The

generator 62 thereupon sends a current out upon the line of subscriber No. 2, the circuit being as follows: Generator 62, wire 61, contact members 53, 52, line 58' to subscribefs station, thence back to line wire 66 to contact members 55, 56; wire 68, wire 67 to generator 62. This rings up subscriber No. 2, who removes his receiver in the usual manner and thus establishes the talking circuit between his station and that of subscriber The call having been made by the central operator, the push rod 76 assumes the position indicated in the center of Fig. 2, so that the contact members 52, 55 resume their normal positions in contact with the members 51, 54. The talking circuit is now established between the two subscribers stations as indicated in Fig. 4, and may be traced as follows: Line wire 58 of subscriber No. 2, contact members 52, 51, wire 57, conducting strip 39, contact strip 11., conducting strip.39 relating to station No. 1, wire 63, contact members 51, 52 relating to station No. 1, line wire 64 to station No. 1, thence returning by line wire 65, contact members 55, 54, wire 70, conducting strip 40, contact strip 10, conducting strip 40, wire 69, contact members 54, 55, and line wire 66 back to station No. 2. The descent of the rod 38, owing to the movement of the bell crank lever 73 as above described, causes a pair of springs 14', 16; 14 16; and 14 16 to make engagement with each other as indicated at the bottom of Fig. 2. This engagement completes a circuit through one of the lamps 20, 20 20 which may be traced as follows Battery 19, lamp 20*, wire 18*, springs 16 14, wire 17 wire 17 back to battery 19. The lamp 20 being lighted serves as a busy signal and prevents the operator from disturbing the connection. To ring off, either subscriber applies his generator to the line in the usual manner, and the operator is apprised that the conversation is finished, the circuit being traced in Fig. 1 as follows Line wire 64, contact members 52, 51, wire 63, shunt wire 89, relay 86, wire 88, wire 70, contact members 54, 55 and line wire back to the station ringing off, say station No. 1. This energizes the relay 86 as in calling and closes the contacts 87', 87 a so that the circuit through the magnet 77 is now completed and the armature 78 pulls the pawl- 7 9 downward, thus releasing the push rod 76 and legying the apparatus in condition for another ca It will be seen from the above that the operator is apprised of a call by the push rod 76 of the station making the call, this rod springing outward, and that during the time that connection is made between two stations a busy lamp 20, 20 is burning. When the pawl 79 engages the tooth 85 as indicated in the center of Fig. 2 and the magnet 77 is energized, the tooth 85 is released and the rod springs back, that is, to the right accord ing to the figure, the point 79 of the pawl engaging the tooth 83. The magnet 77 being immediately thereafter denergized, the pawl springs up so that the point 79 releases the tooth 83, but the tooth 84 is immediately engaged so that the tooth 84 cannot get past the pawl until the magnet 77 is again energized.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 2- 1. In a telephone switch board, the com bination of a source of electricity, a plurality of busy signals adapted to be energized thereby, contacts connected with said busy sig nals, said contacts being normally open, and mechanism for connecting one subscribers circuit with another, said mechanism includ ing a plurality of movable members, said contacts being disposed within the respective paths of said movable members and adapted to be closed by said movable members.

2. In a telephone switchboard, the combination of a plurality of contacts, subscribers lines connected with said contacts, connecting strips situated adjacent to said contacts, said contacts being adapted to be brought into and. out of communication with each other through said. connecting strips, a push. rod provided with mechanism for bringing said contacts in connection with said connecting strips when the push rod is moved in one direction from. its normal position, a spring for forcing said push rod in the opposite direction beyond its normal position so as toenable it to act as a signal, and mechanism for engaging and holding the rod against the tension of its spring, the said mechanism being electrically operated from subscribers lines for releasing said push rod and consequently disconnecting said contacts from said connecting strips.

3. In a telephone switchboard, the combination of a swinging frame, a hand lever for moving the same into different positions, contacts to be closed by movements of said hand lever, operators circuits connected with said contacts, contact strips mounted upon said swinging frame, a plurality of subscribers lines, contacts connected with said lines, and means for bringing said last-mentioned con tacts in connection with said contact strips.

4. In a'telephone switchboard, the combination of a push rod, a bell crank to be actu ated thereby, a lever connected with said bell crank, conducting strips depending from said lever and movable by the same, contact strips to be engaged and disengaged by said conducting strips, a swinging member carrying said contact strips, means controllable at will for actuating said swinging memher so that the position of said contact strips carried thereby is altered relatively to the general position of said conducting strips, and mechanism controllable at will for connecting said conducting strips with, and disconnecting the same from, the various subscribers lines.

5. In a telephone switchboard, the combination of a swinging frame, a hand lever for moving the same into different angular positions, contact strips mounted on said swinging frame, a multitude of subscribers lines terminating in contacts adjacent to said contact strips, mechanism controllable at the will of the operator, adapted to bring said contacts in connection with said contact strips, busy signal contacts disposed between said contact strips and having no electrical connection therewith but mechanically so arranged that when a subscribers line is thrown in contact with said contact strips, said busy signal contacts are closed, and busy signal circuits connected with said busy signal contacts and so arranged that the operator can determine by said busy signals which of the said contact strips are in use.

6. The combination of a swinging frame, provided with contact strips, a plurality of conducting strips disposed adjacent to the path of said contact strips, subscribers lines connected with said conducting strips, mechanism for moving said. conducting strips endwise so as to place the same into and out of engagement with said contact strips, contact mechanism disposed adjacent to the ends of said conducting strips and adapted to be opened and closed by movements thereof, and busy signals connected with said last-mentioned contact mechanism.

7. In a telephone switchboard, the combi nation of a bracket, a push rod slidably mounted therein and provided with teeth spaced apart in the general direction of the length of said push rod, a pawl disposed adjacent to said push rod and provided with portions to be engaged by said teeth, a mag net for actuating said pawl so as to release the same from said teeth, a spring for retracting said push rod, mechanism connected with said push rod for opening and closing contacts, and a member to be actuated by said push rod, said member being adapted to occupy different relative positions corresponding to the relative positions of said teeth upon said push rod.

8. An electrical switch composed of four stationary contacts and two movable contacts, said movable contacts being adapted to be in electrical connection with two of said stationary contacts at 'one time, subscribers lines connected with said. movable contacts, conducting strips connected with two of said stationary contacts, a circuit for carrying electrical energy for ringing subscribers boll, connected with the other two stationary contacts, and a push rod, said movable contacts being adapted to be actuated by the push rod in such a manner as to release said movable contacts from the stationary contacts which are connected with said conducting strips and to bring said movable contacts in connection with the stationary contacts connected with the ringing circuit.

9. In a telephone switch-board, the combination of a plurality of contacts, subscribers lines connected with said contacts, and adapted to be brought into and out of communication with each other by the closing and opening of said contacts, a push rod mounted to slide, mechanism actuated by the push rod, when the latter is moved in one direction from its normal position, to close said contacts, the said push rod when moved in the other direction from its normal position acting as a signal, a spring for forcing said push rod in the direction to enable it to act as a signal, electrically operated mechanism for engaging the push rod, when the latter is in position to close said contacts, to hold the push rod against the tension of its spring, said mechanism also engaging and holding the rod against the tension of its spring when the rod is in its normal position, the said mechanism being operated from the subscribers lines to release the push rod when the latter is in either of said positions.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN M. DOSBAUGH. l/Vitnesses LOUIS ADAM, J12, EFFIE ADAM. 

